Question

I have a problem of not being able to access configuration and path information outside controller context. I am in a Assetic Filter class that has no methods to help me, and I need to know the kernel path along with some configuration. How do I do the Symfony 1 sfContext::getInstance() call in Symfony 2?

Answer 1

If you are writing an assetic filter you are writing a service. In the service definition you can pass parameters from the DIC. For example you can pass the AppKernel absolute path writing:

<argument>%kernel.root_dir%</argument>

If you want to have a semantic configuration for your filter (and for any service in general) it would reside in a DIC extension. By default “MyNamespaceMyBundle” will register the “MyNamespaceMyExtension” extension class inside the DependencyInjection subpackage and this extension will handle configuration from the “my_namespace_my” top level configuration key creating services or setting DIC parameters.

Moreover you would want to have a Configuration class that handles validation, normalization and merging of your configuration. Sadly all of this is more or less not documented anywhere, so best way to achieve your goal is to look at some other bundle (e.g. I learned very much reading FOSUserBundle).